But I'm more interested in who should move in. President Obama has filled the open slots by promoting others in his administration. That's a sign he's happy with the advice and service he's received over the past two years. And in many ways, he's right to be. This administration entered office with the economy teetering on the edge of the abyss. His team has successfully pulled us onto firmer ground.

The next two years, however, will require new thinking. The problems of an acute crisis have given way to the frustrations of a slow recovery. The large Democratic majorities in the House and Senate are likely to be wiped out by a resurgent Republican Party. Concerns about the deficit won't allow for much in the way of new spending.

The Obama administration needs an agenda suited to these circumstances, and to help them think one up, it needs fresh eyes and new voices.

Here are five suggestions. (Disclaimer: I didn't tell these people I'd be mentioning them, and I'm not personally close with any of them. This is about their ideas, not their personalities.)

1) Karen Kornbluh: In a previous life, Kornbluh was Sen. Obama's policy director. Now, she's serving as our ambassador to the Organization for Economic Cooperation and Development. It's not exactly hard labor. She gets a house in Paris. But it's time Obama called her back.

With health-care reform and the expansion of the Children's Health Insurance Program, the Obama administration has done important work expanding and strengthening the safety net. Now officials need to turn their attention to the focus of Kornbluh's work: modernizing it. These programs were developed in an age when men were the breadwinners, women stayed home to raise children, single-parent families were rare, and workers tended to stick with a single employer for decades. All of that has changed, but our social supports haven't.

Kornbluh's vision is to refocus our entitlements on "juggler families": income-insecure families "juggling to make ends meet and so dependent on the mother's income [that] time off to care for a sick child or a new baby can result in devastating income interruptions and even job loss." Her proposals include updating Social Security so it counts time spent parenting and establishing a family-insurance program that would help earners who have to take time off to care for a child or parents. This sort of thinking is overdue, and you could even imagine it appealing to conservatives interested in supporting families.

2) Mark McClellan: McClellan led the Center for Medicare and Medicaid Services under George W. Bush. He was instrumental in implementing the Medicare prescription drug benefit. That gives him two things the Obama administration definitely needs: credibility with Republicans on health care and experience making a major health-care initiative work.

McClellan has been a cautious friend and frequent critic of the Obama administration's health-care reforms. He complimented the legislation for making important progress on coverage and payment reforms while criticizing it for falling short on medical malpractice and consumer-driven policies. He deserves to be heard out on both points, and if Republicans fail in their efforts to repeal the legislation - and they probably will - some might be interested in having a sympathetic voice on the inside.

3) Dean Baker: Think the administration's economic team is too insular? Baker, a contrarian economist who was among the first to spot the housing bubble and who's been a vocal critic of the administration's economic policies (and The Washington Post's economic coverage), will fix that.

Baker can be counted on for innovative policy thinking. (For instance: How about doing away with pharmaceutical patents? Or letting foreclosed homeowners rent their homes? Or slapping a transaction tax on Wall Street to slow things down and reduce our deficit?) And, perhaps more important, he is uninterested in currying favor with those in power. It's hard to imagine him playing well with others in the White House, but then, that's the point. He'll say things they don't want to hear, but should.

4) Christina Romer: Romer, who just left the White House, won't exactly bring a new perspective. But she brings the right perspective. In her final speech as chairman of the Council of Economic Advisers, she offered the full-throated call for more fiscal stimulus, which the administration has largely abandoned. "Concern about the deficit cannot be an excuse for leaving unemployed workers to suffer," she said. "We have tools that would bring unemployment down without worsening our long-run fiscal outlook, if we can only find the will and the wisdom to use them."

She's right. The stimulus may not poll well, but it worked. Unemployment would've been much higher without it. Was it too small? It was. But Romer knew that at the time. She calculated that we needed $1.2 trillion. We got a bit more than half that, and then the economic crisis proved worse than it seemed when Romer was running the numbers.

Unemployment is now at 10 percent, and though the stimulus probably kept it from brushing 12 percent, the economic misery has turned voters against the intervention. The administration can't hide from this fight, however. The job situation is too grim for the government to simply leave the unemployed to their fate. Romer, speaking freely in her final days in office, had it right.

5) A political scientist: In general, Washington is split between people who specialize in governing (most of them economists or lawyers or public policy graduates) and people who specialize in running elections. Political scientists, who study the history and run the numbers on both pursuits, are not invited to the table. Adding to the snub, the president has hosted at the White House groups of journalists, pundits and historians. Again, no political scientists.

That's a shame, because the White House could use some political science. If the administration wanted out of the 24-hour news cycle that obsesses over who's up and who's down, it should've grabbed some of the people who've studied the waxing and waning of the liberal and conservative brands since the 1930s. (Did you know that on the eve of FDR's 1936 rout of the Republican Party, a majority of Americans polled by Gallup identified themselves as conservative?) The White House, which was shocked by the Republican Party's unwillingness to offer early cooperation, could have benefited from congressional scholars who knew that both history and electoral incentives ensured that Republicans would obstruct from Day One.

I could go on. Pick an issue, or a political quandary, and odds are there's a wealth of political science literature on the topic. The White House needs someone who can bring the profession's best insights and evidence to the administration's deliberations. And I hear there are even free desks for them to sit in.